Problem with rootfs mounting

Hello all, I am porting linux-2.6.37 to a new architecture, and I am facing the well-known problem: VFS: Cannot open root device "(null)" or unknown-block(0,0) When I was working on uClinux, the vmlinux image was concatenated with the romfs image. The kernel was aware of the address of the magic number -rom1fs- thanks the configuration CONFIG_MTD_UCLINUX_ADDRESS= . . . in the .config file. But, I have not found how I can do thit in Linux.. Where and how the romfs tree is created and included to the kernel image? This question concerns also all the necessary user applications like "init" and "sh". Any help will be very useful. Thanks in advance.